Risk factors for mortality from lower respiratory infections in nursing home patients

Little is known about the factors that predict whether nursing home residents with lower respiratory infection (LRI) will do well or poorly, although this information is critically important when making treatment decisions.

Using nursing home and hospital medical records, we performed a case-control study to identify risk factors for death from LRI among residents of a 110-bed, midwestern community nursing home. Three experienced geriatricians aided in the development of an operational definition of an LRI. In a 3 1/2-year period, we identified 26 cases in which the patients died from LRI and 66 control episodes in which the patients recovered from LRI.

Compared with those who survived, those who died were 14 times more likely to be totally dependent with respect to activities of daily living (ADL) than the group of patients least ALD-dependent (odds ratio [OR] = 14; 95% confidence interval [95% CI] = 2.85 to 68.87). After adjusting for ADL, mortality was significantly decreased when a broad-spectrum oral antibiotic (trimethoprim-sulfamethoxazole, cefaclor, amoxicillin-clavulanate, or ciprofloxacin) was used as the initial therapy (OR = .14; 95% CI = .02 to .81).

Better functional status and initial therapy with broad-spectrum oral antibiotics were strong predictors of surviving an LRI in this population of nursing home patients. The antibiotic effect may be a treatment effect or the consequence of underlying factors leading physicians to select particular antibiotics; however, it appears possible to identify low-risk persons who do not require the aggressive treatment and hospitalization that is often recommended for these patients. An approach to the treatment of nursing home LRI is suggested.